Characteristics of juvenile arthritis (JA) and corresponding control groups.
| n | Sex M, %; F, % | Age, yrs mean ± SD | |
|---|---|---|---|
| Oligoarticular | |||
| Oligoarticular JIA | 213 | 34:66 | 6.9 ± 4.3 |
| Olligoarticular control | 515 | 35:65 | 8.5 ± 3.8 |
| Polyarticular | |||
| Polyarticular JIA | 120 | 24:76 | 10.6 ± 4.7 |
| Polyarticular control | 798 | 24:76 | 10.7 ± 4.1 |
| Polyarticular RF– | |||
| Polyarticular RF− | 92 | 27:73 | 9.8 ± 4.8 |
| Polyarticular RF− control | 824 | 27:73 | 10.6 ± 4.2 |
| Polyarticular RF+ | |||
| Polyarticular RF+ JIA | 28 | 14:86 | 13.2 ± 3.3 |
| Polyarticular RF+ control | 578 | 14:86 | 13.2 ± 3.1 |
| Systemic | |||
| Systemic JIA | 40 | 60:40 | 7.4 ± 4.8 |
| Systemic control | 197 | 59:41 | 9.9 ± 4.3 |
JIA: juvenile idiopathic arthritis; RF−: rheumatoid factor negative; RF+: rheumatoid factor positive.